Symbolism: from one, many
As a creative writer who loves to write fiction of all sorts, I appreciate symbolism for its ease of use and its potential to strike emotional chords within my readers.
It's a lot of fun to choose symbols for a work of fiction, because even the simplest ones can have a diverse array of meanings, as Shanelle mentioned on her blog. Sometimes, your readers go back and discover possible meanings that even you, the writer, didn't notice at first.
This, of course, presents a problem in some ways: a writer might want readers to have a particular emotional response to a symbol, in order to prepare them for an upcoming plot event, but they might completely miss the cue or even interpret it in unexpected ways. I think the best solution to this problem is to place the symbol in a context that supports the intended meaning, in order to better guide readers to it -- though that can present a significant challenge.